- From: Luc Moreau <l.moreau@ecs.soton.ac.uk>
- Date: Sun, 25 Nov 2012 10:39:10 +0000
- To: public-prov-wg@w3.org
Thanks Jun, It's archived in http://lists.w3.org/Archives/Public/public-gld-comments/2012Nov/0003.html Luc On 25/11/12 09:44, Jun Zhao wrote: > Thanks Paul, and Luc for his offline support. > > The comments are now sent back to public-gld-comments@w3.org. > > Many thanks! > > -- Jun > > On 11/23/12 11:44 AM, Paul Groth wrote: >> I'm fine with this. >> >> Paul >> >> >> On Fri, Nov 23, 2012 at 10:22 AM, Jun Zhao <jun.zhao@zoo.ox.ac.uk> >> wrote: >> >>> Dear all, >>> >>> Please find below the draft response that Luc and I prepared for the >>> last call for comments by the eGov WG regards to the Organization >>> Ontology (http://www.w3.org/News/2012.html#entry-9606). >>> >>> It will become the group response unless we hear objections by Saturday >>> Midnight GMT, November 24th. >>> >>> Many thanks! >>> >>> -- Jun >>> >>> >>> >>> ==================================================================================== >>> >>> >>> Dear Organization Ontology Editors, >>> >>> The PROV WG reviewed the part of the document about extension to PROV. >>> Generally speaking we agree with your following extensions: >>> >>> - org:originalOrganization as a subproperty of prov:used, >>> - org:resultedFrom as a subproperty of prov:wasGeneratedBy >>> - org:ChangeEvent as a subclass of prov:Activity >>> >>> In addition, we would like to draw your attention to the concept of >>> derivation [1] in PROV, which refers to a transformation of an entity >>> into another, an update of an entity resulting in a new one, or the >>> construction of a new entity based on a pre-existing entity. Based on >>> some general knowledge, one might expect that a new organization should >>> be a derivation of the old one, by some sort of transformation or >>> update >>> or simply setting up a new entity. But does this indeed make sense with >>> the use cases that you consider? >>> >>> This is a strong albeit useful assertion, enabling you to trace the >>> history of an organization. However, the semantics of the PROV model >>> does not let you infer this relationship by the combination of >>> generation and usage, i.e., from the following triples: >>> >>> ex:o2 org:resultedFrom ex:a1 >>> ex:a1 org:originalOrganization ex:o1 >>> >>> The PROV model regards ex:o1 and ex:o2 as totally unrelated, unless >>> their relationship is explicitly stated otherwise. If the definition of >>> derivation does fit your use case, making use of this relationship in >>> your ontology will make it much more in line with the upcoming >>> provenance recommendation. So it is a matter to have a think about what >>> you intend to achieve by using the prov:used and prov:wasGeneratedBy >>> properties. If you want to include derivation in your ontology, then we >>> make the following to suggestions: >>> >>> 1. We RECOMMEND that ex:o2 prov:wasDerivedFrom ex:o1 be explicitly >>> asserted. (or a subproperty in the org: namespace) >>> 2. Alternatively, you could add a property chain >>> org:resultedFrom followed by org:originalOrganization => >>> prov:WasDerivedFrom >>> >>> >>> The second point is that the PROV model comes with a set of implicit >>> semantics constraints (in its constraint document [2]). Although these >>> constraints are not reflected in the PROV-O, we expect that a >>> provenance >>> validator, compliant with this document, will validate provenance >>> statements on the Web. Therefore, it might be worthwhile to take a >>> pause >>> and think whether the intention behind your ontology might lead to any >>> violation to relevant constraints. >>> >>> For example, the generation-precedes-usage constraint [3] requires that >>> the event when a new organization was generated must precede the event >>> when the same organization was used in the process of generating >>> another >>> organization. >>> >>> >>> Finally, we would also like to bring your attention to the concept of >>> invalidation. In the PROV data model we say that an entity can have a >>> lifetime. And the invalidation is the start of the destruction, >>> cessation, or expiry of an existing entity by an activity [4]. >>> >>> If this concept is adopted in the Organization Ontology, then you will >>> be able to specify more precisely that the cease-to-exist of the old >>> organization when a new organization was built up. Might this be >>> helpful >>> to your use cases? >>> >>> Please be aware that by using this concept, there are several related >>> constraints to bear in mind. An example is the >>> usage-precedes-invalidation constraint [5], which means that the event >>> when an old organization ceased to exist must follow the event when it >>> was used in the org:ChangeEvent activity. >>> >>> We, the WG as a whole, will be happy to help you with any other issue >>> related to PROV. >>> >>> Hope this helps. >>> >>> Jun, on behalf of the PROV WG >>> >>> [1] http://www.w3.org/TR/prov-dm/#term-Derivation >>> [2] http://www.w3.org/TR/2012/WD-prov-constraints-20120911/ >>> [3] >>> >>> http://www.w3.org/TR/2012/WD-prov-constraints-20120911/#generation-precedes-usage >>> >>> [4] http://www.w3.org/TR/prov-dm/#term-Invalidation >>> [5] >>> >>> http://www.w3.org/TR/2012/WD-prov-constraints-20120911/#usage-precedes-invalidation >>> >>> >>> >>> >>> >> > > -- Professor Luc Moreau Electronics and Computer Science tel: +44 23 8059 4487 University of Southampton fax: +44 23 8059 2865 Southampton SO17 1BJ email: l.moreau@ecs.soton.ac.uk United Kingdom http://www.ecs.soton.ac.uk/~lavm
Received on Sunday, 25 November 2012 10:39:43 UTC